Dynamics of Merkel Cell Patterns in Developing Hair Follicles in the Dorsal Skin of Mice, Demonstrated by a Monoclonal Antibody to Mouse Keratin 8

The study investigated the development of Merkel cells and nerve endings in the dorsolateral skin of C57BL mouse embryos using a monoclonal antibody to mouse keratin 8. It was found that Merkel cells appeared in the developing tylotrich follicles and adjacent epidermis around 15 days of gestation, forming a disc-shaped rudiment by 16 to 17 days. No Merkel cells were associated with awl and zigzag follicles, and in Tabby mutant mice, which lack tylotrich follicles, Merkel cells were absent. However, in downy mutant mice, Merkel cell development was similar to wild-type mice. Nerve endings were identified in the dermal mesenchyme but did not contact the epidermis or follicle epithelium, suggesting that Merkel cell differentiation is independent of neural influences and linked to tylotrich follicle development.